aweful cracking sound ,need help

BOY that is hard to say.

Other than above.................

In this digital age, I'd be tempted to tape/ fasten a GoPro or other recording device under there in two three different places and see if you can run it down. You might also get a helper in a parking lot, say, with a bicycle, etc, and do some low speed turns

As old as these girls are, it can be lots of things from simple/ inexpensive, to something broke/ cracked. Bushing worn, dried out, loose, or even damaged/ rusted structure.